Army Times reports that the Army has developed a new hybrid device that can reduce the noise, recoil, and flash of a variety of weapons including those common in the Coast Guard. It functions as a muzzle break to reduce recoil that adversely effects accuracy, as a suppressor to reduce noise that may cause hearing loss without the usual adverse effects of a suppressor, and as a flash hider.
“It’s a hybrid device that cuts half the volume at the shooter’s ear, reduces recoil by a third and drops volume down range by one quarter, said Gregory Oberlin, a small arms engineer at the Army’s Combat Capabilities Development Center Army Research Lab.”
Chuck Hill's CG Blog 
There’s nothing very new or advanced here. Many civilian companies have been paving the way in suppressor design, and have even integrated weapon design and suppressor design to make an even more capable system.
Insofar as the CG goes, the VBSS and MSSTs could really benefit from a short suppressor on the Mk.18 (as well as a caliber change). Firing a short-barrelled, High gas expansion cartridge in a passageway or compartment is going to result in hearing loss, even with earpro and muffs. Mk.18s in 300 Blackout with a short/efficient suppressor (even smaller than this Army example) would combine with hearing protection to prevent ear damage. The 300 Blackout in supersonic form is about equivalent to the first assault rifle cartridge, the 7.92x33mm Kurz, and effective for long-ish shots of 200-250m, plenty for use aboard ship.
Reflex suppressors are the way to go if a firearm shall not get much longer or front heavier despite using a suppressor.
https://gunsmith-guncraft.co.za/reflex-vs-standard-silencers/
I do not remember any boarding scene from the 20th century or later that placed much emphasis on how well-armed the boarding team was. The will to resist should rather be broken by a high explosive warning shot than by a rambo boarding team.
The boarding team should wear safety equipment, tools and a handgun (WITHOUT an attached flashlight).
Captive piston handguns are the way t go if you want to avoid excessive noise inside tight, echoing rooms. Those are no louder than if you pull a trigger on a dummy round. They have been understood to be the way to go since Vietnam’s tunnel rats. Their smell is more like ‘KGB’ than ‘Navy SEALS special tacticool operator’, though.